This invention relates to an electric motor and more particularly to an electric motor including a reduction gear mechanism constituted by a variable speed gearing accomodated in a gear box, such as in an electric fan.
Conventional electric motors for fan have had the motor bracket and the reduction gear box formed into a unitary structure by die-casting aluminum. A mould for moulding such a unitary structure is inevitably complicated and the number of components forming the mould has become large while the die-casting operation has been because the moulding material used is aluminum, the moulding as a moulding material involved is aluminum, a moulding temperature is high which has lowered the accuracy of the castings resulting in the necessity of machining the castings.
Accordingly, it is an object of the present invention to provide a new and improved electric motor having high dimensional accuracy sufficient to eliminate the necessity of machining the product as die cast and which has good mass producibility which makes it inexpensive.